A method for surface modification of an interventional catheter

Abstract

The present invention discloses a method for surface modification of an interventional catheter, which comprises the following steps: S1: preparing a catheter using polyurethane particles, and drying the catheter after cleaning; S2: adding acrylic acid and acrylamide into an acetic acid aqueous solution to form a mixed solution; S3: adding chitosan and ammonium persulfate into the mixed solution to react and synthesize a prepolymer; S4: adding 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane into the prepolymer, and preparing a high molecular hydrogel under ultraviolet light irradiation; S5: immersing the catheter into the hydrogel solution; S6: when the temperature of the ultraviolet light irradiator rises to 60-70 °C, after introducing nitrogen, transferring the hydrogel solution in S5 to the ultraviolet light irradiator and irradiating with ultraviolet light; the irradiation time is preferably 60 min. S7: taking out the catheter, cleaning and drying it. The present invention improves the lubricity of the catheter, thereby reducing the friction coefficient, and at the same time can also improve the blood compatibility and antibacterial property of the catheter surface.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and particularly to a method for surface modification of an interventional catheter. Background Art

[0002] As a biomedical material, the material of an interventional catheter must meet the conditions for biomedical applications. At present, biomedical materials generally refer to a class of special functional materials, natural or synthetic, that can directly contact the physiological system and interact with cells, tissues, and organs for diagnosis, replacement, repair, or induction of regeneration. The performance of a medical interventional catheter depends on its manufacturing material, and its use effect is closely related to the patient's experience. As one of the most commonly used interventional treatment devices, the material selection of an interventional catheter must be cautious. As a medical interventional catheter material, its performance must meet the following basic conditions: having excellent biocompatibility, having good mechanical properties, having good hydrophilic lubricity, and having good processability. How to improve the comprehensive performance of an interventional catheter has always been the research focus in this field. Summary of the Invention

[0003] The present invention provides a method for grafting and polymerizing a hydrophilic coating on the surface of a polyurethane catheter by ultraviolet grafting to improve its lubricity, thereby reducing the friction coefficient, improving the blood compatibility and antibacterial properties of the material, and enhancing the comprehensive performance of the catheter. The specific technical solutions are as follows.

[0004] A method for surface modification of an interventional catheter, characterized by comprising the following steps:

[0005] S1: Prepare a catheter using polyurethane particles, and dry the catheter after cleaning;

[0006] S2: Add acrylic acid and acrylamide to an acetic acid aqueous solution to form a mixed solution;

[0007] S3: Add chitosan and ammonium persulfate to the mixed solution to react and synthesize a prepolymer;

[0008] S4: Add 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane to the prepolymer, and prepare a high molecular hydrogel under ultraviolet light irradiation;

[0009] S5: Immerse the catheter in the hydrogel solution;

[0010] S6: When the temperature of the ultraviolet light irradiator rises to 60 - 70 °C, transfer the hydrogel solution in S5 to the ultraviolet light irradiator after introducing nitrogen, and irradiate with ultraviolet light; the irradiation time is preferably 60 min.

[0011] S7: Take out the catheter, clean it, and dry it.

[0012] Further, in the step S2, the amounts of substance of acrylic acid and acrylamide are the same.

[0013] Further, the aqueous acetic acid solution is a 2% aqueous acetic acid solution.

[0014] Further, in the step S4, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane accounts for 1%-1.8% of the mass of the prepolymer.

[0015] Further, in the step S6, the aeration time of nitrogen is 8-10 min; the ultraviolet light irradiation is 60 min, and the distance between the catheter and the ultraviolet lamp is 18-20 cm.

[0016] Further, in the step S7, ultrasonic cleaning is performed with ethanol for 7-8 h, then cleaning is carried out in water for 24 h, and subsequently it is placed in a drying oven at 60-70 °C for drying until the weight no longer changes.

[0017] Chitosan (CS) is a natural polysaccharide biological macromolecule with a unique molecular structure, and it has the advantages of being safe and non-toxic, biodegradable, having good film-forming properties, good biocompatibility, antibacterial properties, etc. Ammonium persulfate is used as a reaction initiator. Hydrogel is a natural or synthetic polymer network with high water absorbency (the water content can reach more than 90%). And the hydrogel contains a large number of carboxyl groups, and the carboxyl groups can form hydrogen bonds with water, making it have good hydrophilicity.

[0018] Surface modification of the interventional catheter is one of the effective methods to inhibit the coagulation reaction. The surface modification uses acrylic acid (AA) and acrylamide (AM), and through ultraviolet grafting technology, it is grafted and polymerized on the surface of the polyurethane material to improve the hydrophilicity and antibacterial properties of the material surface. Acrylic acid and acrylamide are used as raw materials for the hydrogel, and polyacrylic acid hydrogel is used as an adsorbent, which has an adsorption effect on metal ions. The amide bond (N—H) in acrylamide can be obtained to form a compound with a chloramine structure (N—Cl) after the action of sodium hypochlorite. The N—Cl bond is decomposed under the action of water molecules and releases positively charged chloride ions with an oxidation effect. The positively charged chloride ions can react with some active functional groups in microorganisms to kill them, and the hydrogel contains a large number of carboxyl groups, and the carboxyl groups can form hydrogen bonds with water, resulting in its good hydrophilicity. Chitosan (CS) has good biocompatibility in biology, special biological activities (such as hemostasis, promoting wound healing, preventing tissue adhesion, etc.), and also has natural antibacterial properties. The method of the present invention not only improves the lubricity of the catheter, but also can improve the blood compatibility and antibacterial properties of the catheter, making the interventional catheter more operable, reducing the damage to tissues such as blood vessels and blood cells, and avoiding coagulation caused by mechanical shearing when the hard-surfaced interventional catheter moves in the blood vessel. Another purpose of the surface modification is to improve the antibacterial adhesion ability of the interventional catheter and prevent complications such as sepsis or phlebitis caused by interventional treatment. Brief Description of the Drawings

[0019] Figure 1 are the grafting rate test results of the examples and the comparative examples;

[0020] Figure 2 is the synthesis video diagram of the hydrogel;

[0021] Figure 3 is the scanning electron microscope image of the platelet adhesion experiment of the polyurethane catheter;

[0022] Figure 4 is the scanning electron microscope image of the platelet adhesion experiment of the catheter in Example 5;

[0023] Figure 5 is the scanning electron microscope image of the platelet adhesion experiment of the catheter in Comparative Example 5. Detailed Description of the Invention

[0024] The present invention will be further described below in conjunction with specific examples:

[0025] Example 1

[0026] S1: Press a certain amount of medical polyurethane particles into a catheter, ultrasonically clean for 10 min, and then place it in an electrothermal constant temperature blast drying oven for 24 h for standby;

[0027] S2: Prepare a 2% acetic acid aqueous solution, and then add acrylic acid and acrylamide in the same amount of substance to an appropriate amount of acetic acid aqueous solution to form a mixed solution.

[0028] S3: Add chitosan (CS) to the mixed solution to react with ammonium persulfate to synthesize a prepolymer.

[0029] S4: Add 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane (DHBP) (1% of the total monomer mass) to the prepolymer, and under ultraviolet light irradiation, prepare a high molecular weight hydrogel. The synthesis route diagram of the hydrogel is as Figure 2 shown.

[0030] S5: Immerse the weighed polyurethane (PU) catheter (m1) into the hydrogel solution;

[0031] S6: When the temperature of the ultraviolet light irradiator rises to 60 °C, after introducing nitrogen for 8 min, transfer the petri dish containing the hydrogel solution into it and irradiate with a high-pressure mercury lamp;

[0032] S7: Subsequently, the catheter is removed from the ultraviolet light irradiator and ultrasonically cleaned with ethanol for 7 h. Then wash it in water for 24 h, and then place it in an electrothermal constant temperature blast drying oven at 60 °C for drying until the weight no longer changes, obtaining the surface-modified catheter.

[0033] Example 2

[0034] S1: Press a certain amount of medical polyurethane particles into a catheter, ultrasonically clean it for 15 min, and then dry it in an electrothermal constant temperature blast drying oven for 24 h for standby;

[0035] S2: Prepare a 2% acetic acid aqueous solution with acetic acid, and then add acrylic acid and acrylamide in the same amount of substance to an appropriate amount of acetic acid aqueous solution to form a mixed solution.

[0036] S3: Add chitosan (CS) to the mixed solution to react with ammonium persulfate to synthesize a prepolymer.

[0037] S4: Add 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane (DHBP) (1.2% of the total monomer mass) to the prepolymer, and under ultraviolet light irradiation, prepare a high molecular weight hydrogel.

[0038] S5: Immerse the weighed polyurethane (PU) catheter (ml) into the hydrogel solution;

[0039] S6: When the temperature of the ultraviolet light irradiator rises to 70 °C, after introducing nitrogen for 10 min, transfer the petri dish containing the hydrogel solution into it and irradiate it with a high-pressure mercury lamp;

[0040] S7: Subsequently, the catheter is removed from the ultraviolet light irradiator and ultrasonically cleaned with ethanol for 8 h. Then wash it in water for 24 h, and then place it in an electrothermal constant temperature blast drying oven at 70 °C to dry until the weight no longer changes, obtaining a surface-modified catheter.

[0041] Example 3

[0042] S1: Press a certain amount of medical polyurethane particles into a catheter, ultrasonically clean it for 10 min, and then dry it in an electrothermal constant temperature blast drying oven for 24 h for standby;

[0043] S2: Prepare a 2% acetic acid aqueous solution with acetic acid, and then add acrylic acid and acrylamide in the same amount of substance to an appropriate amount of acetic acid aqueous solution to form a mixed solution.

[0044] S3: Add chitosan (CS) to the mixed solution to react with ammonium persulfate to synthesize a prepolymer.

[0045] S4: Add 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane (DHBP) (1.4% of the total monomer mass) to the prepolymer, and under ultraviolet light irradiation, prepare a high molecular weight hydrogel.

[0046] S5: Immerse the weighed polyurethane (PU) catheter (ml) into the hydrogel solution;

[0047] S6: When the temperature of the UV irradiator rises to 60°C, nitrogen is introduced for 8 minutes, and then the culture dish containing the hydrogel solution is transferred into it and irradiated with a high-pressure mercury lamp;

[0048] S7: The catheter was then removed from the UV irradiator and ultrasonically cleaned with ethanol for 7 hours, then cleaned in water for 24 hours, and then placed in a 60°C electric constant temperature blast drying oven for drying until the weight no longer changed, thereby obtaining a surface-modified catheter.

[0049] Example 4

[0050] S1: A certain amount of medical polyurethane particles are pressed into a catheter, ultrasonically cleaned for 15 minutes, and then placed in an electric constant temperature blast drying oven for 24 hours for use;

[0051] S2: Acetic acid is prepared into a 2% acetic acid aqueous solution, and then acrylic acid and acrylamide are added with an appropriate amount of the acetic acid aqueous solution according to the same amount of substances to prepare a mixed solution.

[0052] S3: adding chitosan (CS) and ammonium persulfate into the mixed solution to react and synthesize a prepolymer.

[0053] S4: Add 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane (DHBP) (1.6% by weight of the total monomer) to the prepolymer, and prepare a polymer hydrogel under ultraviolet light.

[0054] S5: Immerse the weighed polyurethane (PU) catheter (ml) into the hydrogel solution;

[0055] S6: When the temperature of the UV irradiator rises to 70°C, nitrogen is introduced for 10 min, and the culture dish containing the hydrogel solution is transferred into it and irradiated with a high-pressure mercury lamp;

[0056] S7: The catheter was then removed from the UV irradiator and ultrasonically cleaned with ethanol for 8 hours, then cleaned in water for 24 hours, and then placed in a 70°C electric constant temperature blast drying oven for drying until the weight no longer changed, thereby obtaining a surface-modified catheter.

[0057] Example 5

[0058] S1: A certain amount of medical polyurethane particles are pressed into a catheter, ultrasonically cleaned for 10 minutes, and then placed in an electric constant temperature blast drying oven for 24 hours for use;

[0059] S2: Acetic acid is prepared into a 2% acetic acid aqueous solution, and then acrylic acid and acrylamide are added with an appropriate amount of the acetic acid aqueous solution according to the same amount of substances to prepare a mixed solution.

[0060] S3: adding chitosan (CS) and ammonium persulfate into the mixed solution to react and synthesize a prepolymer.

[0061] S4: Add 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane (DHBP) (1.8% by weight of the total monomer) to the prepolymer, and prepare a polymer hydrogel under ultraviolet light.

[0062] S5: Immerse the weighed polyurethane (PU) catheter (ml) into the hydrogel solution;

[0063] S6: When the temperature of the UV irradiator rises to 60°C, nitrogen is introduced for 8 minutes, and then the culture dish containing the hydrogel solution is transferred into it and irradiated with a high-pressure mercury lamp;

[0064] S7: The catheter was then removed from the UV irradiator and ultrasonically cleaned with ethanol for 7 hours, then cleaned in water for 24 hours, and then placed in a 60°C electric constant temperature blast drying oven for drying until the weight no longer changed, thereby obtaining a surface-modified catheter.

[0065] Comparative Example 1

[0066] S1: A certain amount of medical polyurethane particles are pressed into a catheter, ultrasonically cleaned for 10 minutes, and then placed in an electric constant temperature blast drying oven for 24 hours for use;

[0067] S2: Acetic acid is prepared into a 2% acetic acid aqueous solution, and then acrylic acid and acrylamide are added with an appropriate amount of the acetic acid aqueous solution according to the same amount of substances to prepare a mixed solution.

[0068] S3: adding chitosan (CS) and ammonium persulfate into the mixed solution to react and synthesize a prepolymer.

[0069] S4: Adding diisocyanate (ADI) (1% by weight of the total monomer) to the prepolymer, and preparing a polymer hydrogel under ultraviolet light.

[0070] S5: Immerse the weighed polyurethane (PU) catheter (ml) into the hydrogel solution;

[0071] S6: When the temperature of the UV irradiator rises to 60°C, nitrogen is introduced for 8 minutes, and then the culture dish containing the hydrogel solution is transferred into it and irradiated with a high-pressure mercury lamp;

[0072] S7: The catheter was then removed from the UV irradiator and ultrasonically cleaned with ethanol for 7 hours, then cleaned in water for 24 hours, and then placed in a 60°C electric constant temperature blast drying oven for drying until the weight no longer changed, thereby obtaining a surface-modified catheter.

[0073] Comparative Example 2

[0074] S1: A certain amount of medical polyurethane particles are pressed into a catheter, ultrasonically cleaned for 15 minutes, and then placed in an electric constant temperature blast drying oven for 24 hours for use;

[0075] S2: Prepare a 2% aqueous acetic acid solution, and then add acrylic acid and acrylamide in the same amount of substance to an appropriate amount of the aqueous acetic acid solution to form a mixed solution.

[0076] S3: Add chitosan (CS) and ammonium persulfate to the mixed solution to react and synthesize a prepolymer.

[0077] S4: Add (1.2% of the total monomer mass) diisocyanate (ADI) to the prepolymer, and under ultraviolet light irradiation, prepare a high molecular weight hydrogel.

[0078] S5: Immerse the weighed polyurethane (PU) catheter (ml) into the hydrogel solution;

[0079] S6: When the temperature of the ultraviolet light irradiator rises to 70 °C, after introducing nitrogen for 10 min, transfer the petri dish containing the hydrogel solution into it and irradiate with a high-pressure mercury lamp;

[0080] S7: Then the catheter is removed from the ultraviolet light irradiator and ultrasonically cleaned with ethanol for 8 h. Then it is washed in water for 24 h, and then placed in an electrothermal constant temperature forced air drying oven at 70 °C to dry until the weight no longer changes, obtaining the surface-modified catheter.

[0081] Comparative Example 3

[0082] S1: Press a certain amount of medical polyurethane particles into a catheter, ultrasonically clean for 10 min, and then place it in an electrothermal constant temperature forced air drying oven to dry for 24 h for standby;

[0083] S2: Prepare a 2% aqueous acetic acid solution, and then add acrylic acid and acrylamide in the same amount of substance to an appropriate amount of the aqueous acetic acid solution to form a mixed solution.

[0084] S3: Add chitosan (CS) and ammonium persulfate to the mixed solution to react and synthesize a prepolymer.

[0085] S4: Add (1.4% of the total monomer mass) diisocyanate (ADI) to the prepolymer, and under ultraviolet light irradiation, prepare a high molecular weight hydrogel.

[0086] S5: Immerse the weighed polyurethane (PU) catheter (ml) into the hydrogel solution;

[0087] S6: When the temperature of the ultraviolet light irradiator rises to 60 °C, after introducing nitrogen for 8 min, transfer the petri dish containing the hydrogel solution into it and irradiate with a high-pressure mercury lamp;

[0088] S7: Subsequently, the catheter was removed from the ultraviolet irradiator and ultrasonically cleaned with ethanol for 7 h. Then it was cleaned in water for 24 h and then placed in an electrothermal constant temperature forced air drying oven at 60 °C to dry until the weight no longer changed, obtaining the surface-modified catheter.

[0089] Comparative Example 4

[0090] S1: A certain amount of medical polyurethane particles were pressed into a catheter, ultrasonically cleaned for 15 min, and then placed in an electrothermal constant temperature forced air drying oven to dry for 24 h for standby;

[0091] S2: Acetic acid was prepared into a 2% acetic acid aqueous solution, and then acrylic acid and acrylamide were added in the same amount of substance to an appropriate amount of acetic acid aqueous solution to form a mixed solution.

[0092] S3: Chitosan (CS) and ammonium persulfate were added to the mixed solution to react and synthesize a prepolymer.

[0093] S4: (1.6% of the total mass of the monomers) Diisocyanate (ADI) was added to the prepolymer, and under ultraviolet lamp irradiation, a polymer hydrogel was prepared.

[0094] S5: The weighed polyurethane (PU) catheter (ml) was immersed in the hydrogel solution;

[0095] S6: When the temperature of the ultraviolet irradiator rose to 70 °C, after introducing nitrogen for 10 min, the petri dish containing the hydrogel solution was transferred into it and irradiated with a high-pressure mercury lamp;

[0096] S7: Subsequently, the catheter was removed from the ultraviolet irradiator and ultrasonically cleaned with ethanol for 8 h. Then it was cleaned in water for 24 h and then placed in an electrothermal constant temperature forced air drying oven at 70 °C to dry until the weight no longer changed, obtaining the surface-modified catheter.

[0097] Comparative Example 5

[0098] S1: A certain amount of medical polyurethane particles were pressed into a catheter, ultrasonically cleaned for 10 min, and then placed in an electrothermal constant temperature forced air drying oven to dry for 24 h for standby;

[0099] S2: Acetic acid was prepared into a 2% acetic acid aqueous solution, and then acrylic acid and acrylamide were added in the same amount of substance to an appropriate amount of acetic acid aqueous solution to form a mixed solution.

[0100] S3: Chitosan (CS) and ammonium persulfate were added to the mixed solution to react and synthesize a prepolymer.

[0101] S4: (1.8% of the total mass of the monomers) Diisocyanate (ADI) was added to the prepolymer, and under ultraviolet lamp irradiation, a polymer hydrogel was prepared.

[0102] S5: Immerse the weighed polyurethane (PU) catheter (ml) into the hydrogel solution;

[0103] S6: When the temperature of the ultraviolet light irradiator rises to 60 °C, after introducing nitrogen for 8 min, transfer the petri dish containing the hydrogel solution into it and irradiate with a high-pressure mercury lamp;

[0104] S7: Subsequently, the catheter is removed from the ultraviolet light irradiator and ultrasonically cleaned with ethanol for 7 h. Then it is washed in water for 24 h, and then placed in an electrothermal constant temperature forced-air drying oven at 60 °C to dry until the weight no longer changes, obtaining the surface-modified catheter.

[0105] Perform relevant performance tests on the surfaces of the polyurethanes after grafting in Examples 1 - 5 and Comparative Examples 1 - 5.

[0106] Grafting rate test: Grafting rate P (%) = (m2 - m1) / m1 × 100%.

[0107] Water absorption rate test: Place the catheters before and after modification in a vacuum drying oven at 75 °C and -0.08 MPa for 3 h, weigh them with an analytical balance (G1), then soak them in distilled water for 2 h, blot the water droplets on the surface with filter paper, and weigh them (G2). The water absorption rate (ρ) is calculated according to the formula ρ (%) = (G2 - G1) / G1 × 100%. Take 5 specimens for each group of experiments and find the average value of the water absorption rate.

[0108] Table 1 shows the test results of the water absorption rate

[0109]

[0110] Surface contact angle test: Dry the catheter and measure the contact angles θH2O and θCH2I2 of water and diiodomethane on the surface of the specimen respectively with a Krüss DSA100E contact angle measuring instrument from Germany, and observe the change of the contact angle over time. The operation method is to take about 5 μL of distilled water (take about 2 μL of diiodomethane) with a micropipette and add it to the surface of the specimen, measure the size of the contact angle, and observe the change of the contact angle over time. The measurement temperature is 20 °C and the humidity is 50%. Take 10 points for each specimen respectively and find the average value of the contact angle.

[0111] Table 2 shows the test results of the contact angle

[0112]

[0113]

[0114] Surface friction coefficient test: Place the modified and unmodified catheters at the other end of a horizontal plane with a fixed pulley. The tensile testing machine gradually increases the tensile force until a slider with a mass of 200 g slides horizontally on the surface of the catheter at a speed of 20 mm / s. At this time, the tensile force displayed by the tensile testing machine (with an accuracy of 0.001 N) is the frictional force. According to the formula of friction factor = (frictional force / slider gravity), calculate the sliding friction factor, measure three times, and take the average value.

[0115] Table 3 shows the test results of the surface friction coefficient

[0116] sample polyurethane catheter Example 1 Example 2 Example 3 Example 4 Example 5 coefficient of friction 0.478 0.103 0.067 0.053 0.042 0.036 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 0.142 0.113 0.082 0.069 0.056

[0117] Platelet adhesion experiment: Place the catheter sample in fresh PRP (platelet-rich plasma), incubate it in a water bath at 37 °C for 1 h, then take it out, gently wash the sample with PBS (135 mmol / L NaCl; 4 mmol / L KCl, 1.5 mmol / L NaH2PO4, 8 mmol / L Na2H2PO4; 0.02% NaN3, I = 0.2, PH = 7.4), and then fix it with 2.0% glutaraldehyde (4 °C, 24 h). After fixation, dehydrate it successively with ethanol gradients of 50%-75%-95%-100% for 10-15 minutes each, and then dehydrate it with isoamyl acetate gradients of 50%-75%-95%-100% (the second component is ethanol) for 10-15 minutes each; then perform CO2 critical point drying, vacuum gold plating, and finally observe the adhered platelets and their morphological changes under a scanning electron microscope.

[0118] Based on the above experimental results, it can be seen that: 1. The grafting rate is from Figure 1It can be clearly seen that the grafting rate increases with the increase of the percentage content of DHBP and ADI, and the grafting situation of DHBP is significantly better than that of ADI. 2. After surface coating modification, the water absorption rate increases significantly. The higher the content of DHBP or ADI in the coating solution, the greater the water absorption rate of the modified polyurethane surface. For the coating solution with the same concentration, the water absorption rate of the polyurethane modified by DHBP is higher than that of the polyurethane modified by the ADI coating. 3. The contact angle reflects the ease of wetting of the surface. The initial contact angle greater than 90° after surface modification indicates obvious hydrophobicity. After equilibrium, under the action of water molecules, there is also an increase in surface polarity caused by the change in molecular chain conformation, so the equilibrium contact angle decreases, and at this time the surface has good hydrophilicity. 4. Acrylic acid and acrylamide not only have strong hydrophilicity, but the positive chloride ions generated by them can react with microorganisms to kill them, playing a sterilization role. This method not only improves the lubricity of the catheter, but also improves the blood compatibility and antibacterial properties of the material surface. Since the modified surface forms a hydrogel structure in water, in water, the modified surface has a low friction coefficient and good lubrication characteristics. As the content of DHBP or ADI in the coating solution increases, the friction coefficient of the modified surface in water is lower, and the lubricity is better. 5. The static platelet adhesion experiment shows that there is very little platelet adhesion on the surface modified by the DHBP coating, and the platelets are not significantly activated. There is also less platelet adhesion on the surface modified by the ADI coating, but both the adhesion amount and the activation degree of platelets are greater than those of the surface modified by the DHBP coating, as Figures 3 - 5 shown. In addition, the interventional catheter material prepared by the present invention significantly improves the surface lubricity and blood compatibility, and in addition, it also improves the antibacterial adhesion ability of the interventional catheter, preventing complications such as sepsis or phlebitis caused by interventional treatment.

[0119] The embodiments of the present invention have been described above in conjunction with the accompanying drawings. Without conflict, the embodiments and the features in the embodiments of the present invention can be combined with each other. The present invention is not limited to the above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Under the inspiration of the present invention, those of ordinary skill in the art can also make many forms without departing from the purpose of the present invention and the scope protected by the claims. All of these belong to the protection scope of the present invention.

Claims

1. A method for surface modification of an interventional catheter, characterized in that, It includes the following steps: S1: Prepare a catheter using polyurethane particles, and dry the catheter after cleaning; S2: Add acrylic acid and acrylamide into an acetic acid aqueous solution to form a mixed solution; S3: Add chitosan and ammonium persulfate to the mixed solution to react and synthesize a prepolymer; S4: Add 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane to the prepolymer, and under the irradiation of an ultraviolet lamp, prepare a high molecular weight hydrogel; S5: Immerse the catheter into the hydrogel solution; S6: When the temperature of the ultraviolet light irradiator rises to 60-70 °C, after introducing nitrogen, transfer the hydrogel solution in S5 to the ultraviolet light irradiator and irradiate it with ultraviolet light; the irradiation time is 60 min; S7: Take out the catheter, clean and dry it.

2. The surface modification method of an interventional catheter according to claim 1, wherein, In the step S2, the amounts of substance of acrylic acid and acrylamide are the same.

3. A method for surface modification of an interventional catheter according to claim 1, characterized in that, The acetic acid aqueous solution is a 2% acetic acid aqueous solution.

4. A method for surface modification of an interventional catheter according to claim 1, characterized in that, In the step S4, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane accounts for 1%-1.8% of the mass of the prepolymer.

5. A method for surface modification of an interventional catheter according to claim 1, characterized in that, In the step S6, the nitrogen introduction time is 8-10 min; the ultraviolet light irradiation is 60 min, and the distance between the catheter and the ultraviolet lamp is 18-20 cm.

6. The surface modification method of an interventional catheter according to claim 1, characterized in that, In the step S7, ultrasonically clean with ethanol for 7-8 h, then clean in water for 24 h, and then place it in a drying oven at 60-70 °C to dry until the weight no longer changes.

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